Larson family mystery

Hey friends!  As of late I have been working to try to decode this mystery for my grandmother.  Now my grandma, Ellen Meeks nee Larson, doesn't know much about her father Edwin's family.  For those of you who are not family who read this and don't know the story I'll give you a brief rundown.  What I started out with was Edwin Larson and his mother Emma nee Lunstrom and his father John Larson.  Now we also knew that Emma got remarried at some point to a man named Herman Palka and they had one daughter, Hazel.  All I ever had on Edwin's father John was the information I got off of Edwin's delayed birth certificate.  Now for those of you who don't know what a delayed birth certificate is, it basically means that child was more than likely not born in a hospital and a birth certificate was not filed until 1 year after the birth.  Now here comes the fun part.  There has always been some speculation, especially as of late, that Herman Palka is actually my great-grandfather Edwin's father.  I think that research I have done so far may not prove that point, but it seems to prove the point that John Larson isn't a real person.  The scary/interesting thing about looking into this matter is that it leads to a loss of identification for my grandmother & her family members with the Larson family name.  If John Larson isn't in fact a real person, then what's the real surname?

Here's what I've found on this matter so far:

• delayed birth certificate from 1894
• lists father as John Larson, age 25, born in Chicago, occupation Wood Turner
• lists mother as Emma Lunstrom, age 24, born in Stockholm
• 1900 census record
• Emma's last name is now Larson & suddenly 6 years later she's now 35
• Herman Palka is a lodger, age 29, German born, occupation Wood Turner
• Edwin's name is Gustave A Larson, & lists his father's birth country as Germany
• 1910 census record
• Emma & Herman are married & daughter Hazel has be born
• Edwin is not listed as having a different name from the rest of the family
• father still listed as German
• 1920 census record
• Edwin is now married, last name is back to Larson
• lists both parents as Illinois births
• Emma Palka death certificate
• her birth place is listed as Sweden
• Father's name: Carl Larsen - born in Sweden
• something to note: this info was given by the informant who is listed as Edwin Palka

All of this has obviously left me with some questions. Where did the last name Lunstrom come from? Is John Larson a real person? Who is my great-grandfather's REAL father? and lastly, what does all this mean for my grandmother?

Hopefully I'll be able to find some more information soon, but I know I can't possibly ever really know the truth.